# How do you solve 3(x-5)=12?

May 3, 2018

$x = 9$

#### Explanation:

$\text{distribute the parenthesis on the left side of the equation}$

$3 x - 15 = 12$

$\text{add 15 to both sides}$

$3 x \cancel{- 15} \cancel{+ 15} = 12 + 15$

$\Rightarrow 3 x = 27$

$\text{divide both sides by 3}$

$\frac{\cancel{3} x}{\cancel{3}} = \frac{27}{3}$

$\Rightarrow x = 9$

$\textcolor{b l u e}{\text{As a check}}$

Substitute this value into the left side of the equation and if equal to the right side then it is the solution.

$3 \left(9 - 5\right) = 3 \times 4 = 12$

$\Rightarrow x = 9 \text{ is the solution}$

May 3, 2018

Isolate x

#### Explanation:

First you want to divide both sides by 3

$\frac{\cancel{3} \left(x - 5\right)}{\cancel{3}} = \frac{12}{3}$

$x - 5 = 4$

$x - \cancel{5} + \cancel{5} = 4 + 5$
$x = 9$